Correlative light and electron microscopy reveals discrepancy between gold and fluorescence labelling

Summary Electron microscopy (EM) is traditionally employed as a follow‐up to fluorescence microscopy (FM) to resolve the cellular ultrastructures wherein fluorescently labelled biomolecules reside. In order to translate the information derived from FM studies to EM analysis, biomolecules of interest must be identified in a manner compatible with EM. Although fluorescent signals can serve this purpose when FM is combined with EM in correlative light and electron microscopy (CLEM), the traditional immunogold labelling remains commonly used in this context. In order to investigate how much these two strategies relate, we have directly compared the subcellular localization of on‐section fluorescence labelling with on‐section immunogold labelling. In addition to antibody labelling of LAMP‐1, bioorthogonal click labelling was used to localize soluble cysteine cathepsins or membrane‐associated sialylated glycans. We reveal and characterize the existence of inherent discrepancies between the fluorescence signal and the distribution of gold particles in particular in the case of membrane‐associated antigens. Lay Description Fluorescence microscopy is a powerful imaging tool that can be employed to track, localize and monitor fluorescently labelled biomolecules within cellular systems. However, using this technique only fluorescently labelled biomolecules can be studied within a given sample, while pertinent information on their immediate cellular environment remains ‘in...
Source: Journal of Microscopy - Category: Laboratory Medicine Authors: Tags: Original Article Source Type: research